Asus P8P67 Pro and "the wall", some observations

[bmg]

I built my new system last week, and it booted up no problem. I worked my way up to 4.7ghz at 1.35v and ran prime and LinX tests for a couple of hours. I moved on to 4.8ghz at the same voltage and booted windows fine, but failed stress tests after a few minutes, so had to power down and then reboot. This is where it gets interesting. I couldn't reboot at anything over 4.4ghz. I removed the battery, did everything I could think of in the bios and no luck. Then when I did something simple like change VCCSA back from .950v to auto, it started to work (trust me, that's not the fix..just happened that one time). I was set again...I tweaked up the voltage to 1.350v and ran tests for hours at 4.8ghz without problems. Then I went to 1.375v and booted at 4.9ghz, but only ran a few minutes of tests, then tried booting at 5.0ghz...lockup and had to power down, and then I was back to not being able to boot above 4.4. After an hour of screwing around again, clearing cmos, etc. something magic happened and I was back in business above 4.4 again.

After awhile I decided to not wait until I locked up again through pushing stress testing and higher frequencies, so I was just running at 4.5ghz, and did a shutdown from windows to see what happens. I powered back up and hung at the windows screen again. I powered up and down a few more times and suddenly I booted ok at 4.5ghz and I was above the "wall" again. I did a windows shutdown again and once more hit the 4.4ghz wall. I haven't gotten back to 4.5ghz and above yet, so I'll probably remove the battery again and screw around again until I "luck" out again and break past the wall again..then I'll be good until I power down again. I've done this enough times to know that eventually by some "random" quirk I'll break through 4.4ghz, and then I'll be fine until another power down. By the way, once it's working I can reboot from windows, tweak stuff in the bios, and things are still fine until a power down. "JJ" or someone else from Asus, can you pass this on to the bios team? Any ideas?

Update: Trust me, I've played around with the "Internal PLL Overvoltage" setting a lot with trying to consistently boot above 4.4. When I'd made this original post I'd temporarily given up on breaking through 4.4ghz, and was running 4.4 and "Internal PLL Overvoltage" on auto. I decided to work on the issue again, rebooted to the bios, set "Internall PLL Overvoltage" to enabled and multiplier to X45 and magically I'm above 4.4ghz again. As I said, I've played around with "Internal PLL Overvoltage" a lot before, so I'm sure I haven't found the magic cure this time, since I've done it all before. Is there a chance that "Internal PLL Overvoltage" is getting set erratically or something? As soon as I have to power down for some reason, I'll likely be back to fighting the problem again. I've gone through this whole cycle like 6-7 times now.

 

[Juan_Jose]

Hello bmg.

A couple of key items you have not noted.

What is your multiplier wall with all bios defaults and just raising the multiplier and the vcore? You can also just run auto tuning extreme with bios defaults and see what the end frequency is.
What bios build are you running?
Are you executing this overclock solely from the UEFI or from windows or a combination of both?
Are you running special memory timings with a manually set divider?
With those questions out of the way I have some feedback.
If it is 44 is your max multi ( without PPL enabled ) then you have a low multi CPU, while you will be able to exceed this value by using the Internal PLL Overvoltage feature keep in mind it is not a guarantee you have a perfect stable experience. This feature was designed to help extend the multiplier range available on the CPU but does not ensure it.

I would advise if you have not to read my overclocking guide to do so carefully and follow the steps there. From the details you have provided you should be able to hold stable at a frequency of approx 4.6 to 4.7 while it is noted you have achieved higher frequencies to ensure stability and consistency I would define your max as one of those multipliers.

As your frequency overall is quite conservative you will really only need to adjust the multiplier and the vcore ( since you like to run unrealistic synthetics ) I would also advise you adjust the phase management option to the 4.8GHz option defined in my OC guide.

Hopefully this helps. Should you have any other questions please let me know. Please enjoy the rest of your day.

 

[Gary Key]

BMG,
One last question to answer please. Have you disabled C-States or EIST, overclocking is different on Sandy Bridge and disabling these features can affect overclocking greatly and create a wall. That said, we have found that disabling S3 will help but leaving the other power management features on auto is best, especially when combining a multi-change and raising bclk at the same time.